The invention relates to an electric radiant heater for heating heating surfaces, as well as to a process and an apparatus for producing the same.
DE-OS No. 27 29 929 discloses a radiant heater, in which the heater coils having a circular cross-section are embedded into the surface of an insulator containing fibrous material by pressing in and which are in this way fixed. Reference is also made therein to the fact that the heater coils can have an oval shape and can be flat, i.e. the smallest extension or small axis thereof is directed towards the heating plate, in order to save overall height.
This type of embedding functions perfectly if the wire thickness of the heater coil does not drop below a certain value and the overall length thereof is not too large compared with the available surface area. However, for many radiant heaters, e.g. those operated in a multitiming circuit, the necessary wire lengths are very large and the wire diameter small, particularly in construction for higher voltages (380 V). In the case of the then necessary limited coil pitches and the reduced coil stability, completely satisfactory fixing is no longer possible.